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-rw-r--r--js/src/frontend/PropOpEmitter.cpp244
1 files changed, 244 insertions, 0 deletions
diff --git a/js/src/frontend/PropOpEmitter.cpp b/js/src/frontend/PropOpEmitter.cpp
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+++ b/js/src/frontend/PropOpEmitter.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "frontend/PropOpEmitter.h"
+
+#include "frontend/BytecodeEmitter.h"
+#include "frontend/ParserAtom.h" // ParserAtom
+#include "frontend/SharedContext.h"
+#include "vm/Opcodes.h"
+#include "vm/ThrowMsgKind.h" // ThrowMsgKind
+
+using namespace js;
+using namespace js::frontend;
+
+PropOpEmitter::PropOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind)
+ : bce_(bce), kind_(kind), objKind_(objKind) {}
+
+bool PropOpEmitter::prepareAtomIndex(TaggedParserAtomIndex prop) {
+ return bce_->makeAtomIndex(prop, ParserAtom::Atomize::Yes, &propAtomIndex_);
+}
+
+bool PropOpEmitter::prepareForObj() {
+ MOZ_ASSERT(state_ == State::Start);
+
+#ifdef DEBUG
+ state_ = State::Obj;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::emitGet(TaggedParserAtomIndex prop) {
+ MOZ_ASSERT(state_ == State::Obj);
+
+ if (!prepareAtomIndex(prop)) {
+ return false;
+ }
+ if (isCall()) {
+ if (!bce_->emit1(JSOp::Dup)) {
+ // [stack] # if Super
+ // [stack] THIS THIS
+ // [stack] # otherwise
+ // [stack] OBJ OBJ
+ return false;
+ }
+ }
+ if (isSuper()) {
+ if (!bce_->emitSuperBase()) {
+ // [stack] THIS? THIS SUPERBASE
+ return false;
+ }
+ }
+ if (isIncDec() || isCompoundAssignment()) {
+ if (isSuper()) {
+ if (!bce_->emit1(JSOp::Dup2)) {
+ // [stack] THIS SUPERBASE THIS SUPERBASE
+ return false;
+ }
+ } else {
+ if (!bce_->emit1(JSOp::Dup)) {
+ // [stack] OBJ OBJ
+ return false;
+ }
+ }
+ }
+
+ JSOp op = isSuper() ? JSOp::GetPropSuper : JSOp::GetProp;
+ if (!bce_->emitAtomOp(op, propAtomIndex_)) {
+ // [stack] # if Get
+ // [stack] PROP
+ // [stack] # if Call
+ // [stack] THIS PROP
+ // [stack] # if Inc/Dec/Compound, Super]
+ // [stack] THIS SUPERBASE PROP
+ // [stack] # if Inc/Dec/Compound, other
+ // [stack] OBJ PROP
+ return false;
+ }
+ if (isCall()) {
+ if (!bce_->emit1(JSOp::Swap)) {
+ // [stack] PROP THIS
+ return false;
+ }
+ }
+
+#ifdef DEBUG
+ state_ = State::Get;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::prepareForRhs() {
+ MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment());
+ MOZ_ASSERT_IF(isSimpleAssignment() || isPropInit(), state_ == State::Obj);
+ MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get);
+
+ if (isSimpleAssignment() || isPropInit()) {
+ // For CompoundAssignment, SuperBase is already emitted by emitGet.
+ if (isSuper()) {
+ if (!bce_->emitSuperBase()) {
+ // [stack] THIS SUPERBASE
+ return false;
+ }
+ }
+ }
+
+#ifdef DEBUG
+ state_ = State::Rhs;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::skipObjAndRhs() {
+ MOZ_ASSERT(state_ == State::Start);
+ MOZ_ASSERT(isSimpleAssignment() || isPropInit());
+
+#ifdef DEBUG
+ state_ = State::Rhs;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::emitDelete(TaggedParserAtomIndex prop) {
+ MOZ_ASSERT_IF(!isSuper(), state_ == State::Obj);
+ MOZ_ASSERT_IF(isSuper(), state_ == State::Start);
+ MOZ_ASSERT(isDelete());
+
+ if (!prepareAtomIndex(prop)) {
+ return false;
+ }
+ if (isSuper()) {
+ if (!bce_->emitSuperBase()) {
+ // [stack] THIS SUPERBASE
+ return false;
+ }
+
+ // Unconditionally throw when attempting to delete a super-reference.
+ if (!bce_->emit2(JSOp::ThrowMsg, uint8_t(ThrowMsgKind::CantDeleteSuper))) {
+ // [stack] THIS SUPERBASE
+ return false;
+ }
+
+ // Another wrinkle: Balance the stack from the emitter's point of view.
+ // Execution will not reach here, as the last bytecode threw.
+ if (!bce_->emit1(JSOp::Pop)) {
+ // [stack] THIS
+ return false;
+ }
+ } else {
+ JSOp op = bce_->sc->strict() ? JSOp::StrictDelProp : JSOp::DelProp;
+ if (!bce_->emitAtomOp(op, propAtomIndex_)) {
+ // [stack] SUCCEEDED
+ return false;
+ }
+ }
+
+#ifdef DEBUG
+ state_ = State::Delete;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::emitAssignment(TaggedParserAtomIndex prop) {
+ MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment());
+ MOZ_ASSERT(state_ == State::Rhs);
+
+ if (isSimpleAssignment() || isPropInit()) {
+ if (!prepareAtomIndex(prop)) {
+ return false;
+ }
+ }
+
+ MOZ_ASSERT_IF(isPropInit(), !isSuper());
+ JSOp setOp = isPropInit() ? JSOp::InitProp
+ : isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper
+ : JSOp::SetPropSuper
+ : bce_->sc->strict() ? JSOp::StrictSetProp
+ : JSOp::SetProp;
+ if (!bce_->emitAtomOp(setOp, propAtomIndex_)) {
+ // [stack] VAL
+ return false;
+ }
+
+#ifdef DEBUG
+ state_ = State::Assignment;
+#endif
+ return true;
+}
+
+bool PropOpEmitter::emitIncDec(TaggedParserAtomIndex prop,
+ ValueUsage valueUsage) {
+ MOZ_ASSERT(state_ == State::Obj);
+ MOZ_ASSERT(isIncDec());
+
+ if (!emitGet(prop)) {
+ return false;
+ }
+
+ MOZ_ASSERT(state_ == State::Get);
+
+ JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec;
+
+ if (!bce_->emit1(JSOp::ToNumeric)) {
+ // [stack] ... N
+ return false;
+ }
+ if (isPostIncDec() && valueUsage == ValueUsage::WantValue) {
+ // [stack] OBJ SUPERBASE? N
+ if (!bce_->emit1(JSOp::Dup)) {
+ // [stack] .. N N
+ return false;
+ }
+ if (!bce_->emit2(JSOp::Unpick, 2 + isSuper())) {
+ // [stack] N OBJ SUPERBASE? N
+ return false;
+ }
+ }
+ if (!bce_->emit1(incOp)) {
+ // [stack] ... N+1
+ return false;
+ }
+
+ JSOp setOp = isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper
+ : JSOp::SetPropSuper
+ : bce_->sc->strict() ? JSOp::StrictSetProp
+ : JSOp::SetProp;
+ if (!bce_->emitAtomOp(setOp, propAtomIndex_)) {
+ // [stack] N? N+1
+ return false;
+ }
+ if (isPostIncDec() && valueUsage == ValueUsage::WantValue) {
+ if (!bce_->emit1(JSOp::Pop)) {
+ // [stack] N
+ return false;
+ }
+ }
+
+#ifdef DEBUG
+ state_ = State::IncDec;
+#endif
+ return true;
+}